AbstractThe microphase separation behavior of H‐shaped (AC)B(CA) ternary block copolymer systems with asymmetric interaction parameters are studied in 3D space by a combinatorial screening method based on SCF theory. The focus is on systems with asymmetric interaction energies among three species, where the Flory‐Huggins interaction parameters obey χAC < χAB = χBC and χAC > χAB = χBC. It is shown that the asymmetric interaction energies enlarge the stable regions of “two‐color” and “three‐color” core/shell microphase morphologies near the three edges of triangle phase diagrams. The “three‐color” hexagonal honeycomb packed cylinder (HEX3‐PC) morphology and the simple cubic spheres connected by cylinders (SCS + C) morphology are found stable.magnified image